ZeniMax, a Maryland-based videogame company, claimed on Thursday that Oculus, a virtual reality hardware company that sold itself to Facebook last month for $2 billion, had broken an agreement that CEO Palmer Luckey would not show the technology to other companies without ZeniMax’s approval. The tech and development came to Oculus by way of John Carmack, a former ZeniMax employee who left the company to join Oculus last year.